System for constructing drain lines

ABSTRACT

A system for constructing a drain line including laying a uniformly thick and contoured bed of particulate material, such as gravel, within the confines of a trench.

United States Patent Lett [ 51 May 23, 1972 [54] SYSTEM FOR CONSTRUCTINGDRAIN LINES [72] Inventor: James E. Lett, 5800 Paula Drive, Knoxville,Tenn. 37912 22 Filed: May 11,1970

21 Appl. No.: 36,021

[52] U.S.Cl ..6l/11,61/72.1

[51] IELC! ..E02b11/02,E02f5/12 [58] Field ofSearch.... ....6l/10,11,41,41 A, 72.1-72.7

[56] Reierenoes Cited UNITED STATES PATENTS 3,203,188 8/1965 Evans..61/72.6

FOREIGN PATENTS OR APPLICATIONS 214,999 8/1967 Sweden ..61/72. 1

Primary Examiner-J. Karl Bell Attorney-Fitch, Even, Tabin and Luedeka[57] ABSTRACT A system for constructing a drain line including laying auniformly thick and contoured bed of particulate material, such asgravel, within the confines of a trench.

9Clairm,5DrawlngFlgures SYSTEM FOR CONSTRUCTING DRAIN LINES Thisinvention relates to the construction of drain fields. The inventionalso relates to systems for laying beds of particular material.

It has been the practice heretofore in the construction of drain fieldsto dig a narrow trench, several feet deep, spread grave] in the bottomof the trench, make a furrow along the approximate center line of thegravel layer and lay tubular tile members end to end in the furrowedbed. The aligned tile members are gradually sloped from one end of thetrench to the opposite end so that liquid matter may flow by gravitythrough the tile members into the gravel bed to become disbursed andeventually absorbed by the adjacent earth. The aligned tile members inthe furrowed gravel are then covered with additional gravel so as tofully encompass the tile member with a selected thickness of gravel.

Heretofore, in drain line construction the gravel has been manuallyspread in the bottom of the trench with shovels or rakes andsubsequently furrowed using hand implements. Obviously this procedurewas time consuming, expensive and in general comprised very arduouslabor. It has been particularly difficult to furrow the gravel becausethe gravel first had to be leveled and then, with great force, movedlaterally to develop the furrow. The tendency of the gravel to roll andtumble back into the furrow as it was pulled out increased thedifficulty of the task. Due to the nature of the work involved, manuallabor for constructing such drain fields is not readily obtainable.

Further, in laying a gravel bed in the bottom of a trench by manuallabor it has been extremely difficult to obtain a uniformly thick layerof the gravel with the result that in many instances excessive gravelhas been consumed thereby increasing the cost of the drain fields. Onthe other hand, it has not been uncommon in such manually laid gravelbeds that the drain tile has been disposed in a bed of gravelinsufficient to convey away the liquid matter fed into the drain fieldfrom the tile, or that the tile was improperly graded to produce thedesired gravity flow of liquid therealong.

It is therefore an object of the present invention to provide aneconomical system for constructing a drain line including laying auniformly thick and contoured bed of particulate material in the bottomof a trench for receipt of drain tile or the like. It is a furtherobject of this invention to provide an apparatus for laying a bed ofparticulate material and having pull bar means accommodating the usualtoothed bucket of a backhoe for propulsion of the apparatus along thelength of the trench. Other objects and advantages of the invention willbecome apparent from the detailed description taken in connection withthe accompanying drawings in which:

FIG. 1 is a schematic representation of the present invention anddepicting various novel features thereof;

FIG. 2 is a fragmentary view of several drain tile disposed in a gravelbed within a trench;

FIG. 3 is a side elevational view of the hopper apparatus of FIG. 1;

FIG. 4 is a top view of the hopper apparatus of FIG. 2; and

FIG. 5 is a front elevational view of the apparatus of FIG. 2.

Briefly stated, the present invention comprehends a system forconstructing a drain line including laying a uniform bed of particulatematerial, i.e., gravel, in the bottom of a trench in position to receivea drain tile or the like. In accordance with the present invention,apparatus such as a backhoe, for excavating a trench and apparatusadapted to be moved along the length of the trench and lay the desiredbed are incorporated into a system whereby a single operatorconsistently can construct uniformly good drain lines in less time andat less cost than has been possible heretofore.

To facilitate an understanding of the present system, a description ofthe desired gravel bed is given. A fragmentary view of a typical bed isshown in FIG. 1. In general, a drain field comprises a system ofinterconnected drain lines each disposed in the approximate center of agravel bed buried several feet beneath the surface of the earth. Eachdrain line usually comprises a plurality of tile members 4 laidend-to-end (butt jointed) without means other than the covering graveland earth for holding the tile in place. It will be appreciated thatliquid effluent passing into the drain line flows by gravity (preferablyvery slowly) along the individual drain lines and through the buttjoints between tiles into the gravel bed 3 where it is dissipated forabsorption by the surrounding earth 2. Other types of tile includespaced openings in the tile wall through which the efiluent is passed tothe gravel bed. In any event, it is the function of the gravel, inaddition to supporting the tile in position, to provide a type ofreservoir effective to receive the effluent and disperse it to the earthfor absorption. In the absence of the gravel, dirt clogs the openings inor between the tiles so as to prevent the discharge of effluent and thusdestroy the effectiveness of the drain field.

The trenches for the drain fields and similar constructions contemplatedin the present invention may be advantageously dug by the use of abackhoe 40 (FIG. 1), i.e., a mechanical digger having a toothed bucket41 which is pivoted on a hydraulically operated arm 42 designed to beswung outwardly to a position of digging. As the arm is pulled backtoward the backhoe, the bucket traverses an arcuate path and digs intothe earth. The bucket is pivoted during its return swing so as tocollect and hold the freshly dug earth within the bucket. This arm andbucket are then raised and moved away from the trench for dumping of theload.

The general concept of the present invention is depicted schematicallyin FIG. 1 and includes a hopper 5 containing a quantity of gravel 35 anddisposed within a narrow trench 36. The hopper is conveniently supportedabove the bottom 37 of the trench on runners 15, 16 and is pulled alongthe length of the trench by a backhoe 40 or the like. As will appearmore fully hereinafter, the bucket teeth 43 of the backhoe may be madeto engage a retractable drawbar 44 disposed on the leading end of thehopper so as to establish a straight line pullforce upon the hopper andmove it along the length of the trench. In the preferred system abackhoe is employed to excavate the trench. After about 16 feet oftrench has been dug, the hopper is lowered into the trench with thefront end of the hopper facing in the direction of excavation and usingthe backhoe to do the lifting. The hopper in the trench is loaded withgravel directly from a dump truck. Using the backhoe, another 10 feet oftrench is excavated. The toothed bucket on the hydraulic arm of thebackhoe is then swung toward the hopper and caused to engage the drawbaron the hopper. The arm of the backhoe is next swung toward the backhoeto pull the hopper forward to the point where the excavation ends. Thebucket is disengaged and a further 10 feet of trench is excavated torecommence the cycle. As the hopper is moved forward in the trench, itlays a bed of gravel which is properly contoured to receive the draintile.

With specific reference to the figures, the apparatus employed in thepresent system includes a hopper 5 of generally rectangularconfiguration having opposite sides 6, 7 and ends 8, 9. Preferably sides6, 7 are of greater dimension than ends 8 and 9. The hopper 5 is open atits top and is provided with a partial bottom 10 (shown in dotted linesin FIG. 1) extending longitudinally between ends 8 and 9. The bottom issealably joined at its points of contact with hopper ends 8, 9 and is ofa lateral dimension such that its edges 11 and 12 terminate inwardly ofhopper sides 6, 7, respectively, so as to define longitudinal slots 13,14 on opposite sides of bottom 10 between its longitudinal edges and thesides of the hopper. Preferably, these slots are coextensive with thelength of the hopper. Moreover, bottom 10 is gabled along itslongitudinal length thereby providing sloping sides extending from thelongitudinal apex of the gable toward the sides of the hopper. Thisgable and sloping sides prevent bridging of particulate material withinthe hopper and promote uniform distribution of the particulate materiallaterally to the slots 13, 14 for dispensing as will be discussedhereinafter.

Hopper 5 is raised above its supporting surface, i.e., the bottom of atrench, preferably by a means of elongated runners 15, 16 disposedbeneath each longitudinal edge of the hopper. Alternatively, wheel meansmay be substituted for the runners but are more costly and lessdesirable. Each runner comprises a gusset 17 defining a leading edge ofthe runner and serving also to assist in joining the runner to theforward end of the hopper. The runners 15, 16 preferably extendrearwardly from their leading edges along substantially the entirelength of the hopper. Further gusset means 19, 20 are provided at therear end of the hopper for connecting the bottom rear end of the hopperto the most rearward end of each runner. Vertical braces (typified bybrace 21) extending between each runner and the lowermost edge of eachside of the hopper are provided intermediate the forward and rearwardends of the hopper as deemed necessary to support the anticipated loadto be contained within the hopper.

In the preferred embodiment, side panel members 22, 23 are providedbetween each runner and the bottom edge of each hopper side to close thespace therebetween. For purposes which will appear hereinafter, thesepanel members preferably extend from the forward ends of runner 15, 16ap proximately one-half of the length of the hopper to define the sidesof a gravel dispensing chute 38, 39 beneath the hopper. In the regionbeneath the hopper and between the side panels 22, 23, there areprovided fender panel members 45, 46 depending from the opposite edgesof bottom 10. Each fender panel is preferably right triangular, havingits base attached to the bottom 10 and its side depending vertically atthe forward end of the hopper. Each fender panel is joined by end panels47, 48 to gussets I7, 18, respectively. Thus, side panel 22, fenderpanel 45, and end panel 48 define a gravel dispensing chute 38 having aneffective volume which decreases from a maximum at its forward end to aminimum at its rear end. A like chute 39 is formed on the opposite sideof the hopper by side panel 23, fender 46, and end panel 47.

The rear end 9 of the hopper is provided with a depending portion 24which converges inwardly and receives a collar 25 (preferably square incross section) at its point of convergence. As may best be seen in FIG.3, a second collar 26 is secured by a structural member 27 to theapproximate central portion of bottom 10. Collar 26 depends from thebottom at a point about halfway between the ends of the hopper and iscoaxial with collar 25. A plow beam 28 (also preferably square in crosssection) is slidably received by the spacedapart collars and therebynonrotatably mounted in trailing relation to the hopper. The extent ofrearward sliding movement of beam 28 within the collars is limited by alug 29 provided on the forward end of beam 28 in position to contact theforward edge of collar 26 as beam 28 is moved in a rearward direction. Atriangular plow blade 30 is fixedly secured to the end of beam 28. Thisplow 30 is disposed at an angle, preferably between about 5 and withrespect to the vertical the inclination of the plow causing its pointedtip 3] to be positioned more rearwardly with respect to hopper 5 thanits uppermost edge 32. That is, plow has a negative angle of attack whenpulled forwardly for purposes to appear hereinafter. The collars 25, 26and their supporting structures 24, 27 may be reinforced by a furtherstrut members (not shown) as necessary. It will be appreciated that beam28 and its supporting framework are wholly confined immediately beneaththe centerline of bottom 10 and do not project laterally such as wouldobstruct the flow of particulate material from hopper 5 through slots13, 14.

The hopper 5, containing its load of gravel and positioned within thetrench, is pulled along the length of the trench by engaging the toothedbucket of the backhoe in a drawbar 44 (FIG. 1) secured at the forwardend of the hopper at its bottom. Drawbar 44 preferably comprises agenerally flat pan member 49 having its forward edge 50 upturned toafford a radiused leading edge so as to permit the pan to slide alongthe dirt bottom of the trench. This radiused leading edge of the panalso serves to receive the teeth 43 of the backhoe bucket 41 in pullingengagement (see dotted outline of FIG. 1). The pan 49 preferably issecured to the hopper by means of a pair of chains 51, 52 disposed onopposite sides of the pan 49 and leading rearwardly through a pair ofopenings 53, 54 on a transverse cross member 55 disposed between gussetsl7 and 18 on the leading edges of runners 15, 16, respectively (see FIG.3). The chains 51, 52 extending through the openings 53, 54 separatelyengage a pair of coil springs 55, 56, one end of each spring engagingeach chain. The springs are anchored at one of their ends to astructural member 57 fixedly secured on the underside of the bottom 10at a point approximately halfway between the opposite ends of the hopper5.

Each of the chains is provided with a pair of stops 58, 59 and 60, 61,one stop on each side of openings 54, 53, respectively in cross member62. It may be visualized that upon the toothed bucket of the backhoeengaging the radiused leading edge of pan 49 and exerting alongitudinally directed pulling force to the pan, the mass of the loadedhopper is sufliciently great to cause springs 55, 56 to become extendedto the point where stops 58 and 60 on chains 52, 51, respectively arecaused to bear against the most rearward edge of openings 54, 53.Thereupon, further pulling force exerted by the backhoe bucket causesthe hopper to be pulled along the trench. When the hopper has reachedthe forward limit of travel which is possible during a single swing ofthe arm of the backhoe, the bucket is disengaged from the pan. When thepulling force is thus released, springs 55, 56 cause pan 49 to beretracted toward the hopper until stops 59 and 61 engage the mostforward edge of openings 54 and 53 and halt the retraction. While thehopper is in the trench, this retrieval action of the springs withdrawsthe pan from that area of the trench within which it is desired torecommence excavation.

In addition to the resiliency provided in the drawbar mechanism, it hasbeen found important in the present invention that this drawbackmechanism include a flexible means for joining the pan 49 to the hopper5. In the preferred embodiment, as set out above, this flexibility isafforded by the chains 51, 52. This flexibility is preferred foraccommodating the necessarily nonlinear movement of the toothed edge ofbucket 41 as the bucket is drawn toward the backhoe 40 by thecombination of pivotal movements of arm 42 and bucket 41. In the absenceof this flexible connection between the point of engagement of thebucket with the drawbar and the point on the hopper where the drawbar isanchored for pulling, the necessarily coarse and gross movements of thetoothed bucket result in frequent disengagement of the bucket from thedrawbar or destruction of the drawbar due to the ap plication of unevenforces by the bucket. In either of the latter events, there willnecessarily result a loss in time and consequential increase in cost ofthe overall operation.

As a further matter of importance in the present invention, it is to benoted that the pulling force exerted by the toothed bucket actingthrough the drawbar mechanism to pull the hopper along the trenchconstitutes a straight-line horizontal pulling force. Pulling forcesapplied to the hopper in other than a straight-line horizontaldirection, such as a force exerted at an upward angle, cause the forwardend of the hopper to be lifted off the bottom of the trench, therebydestroying control over the thickness and contour of the gravel bed.Accordingly, it is unsatisfactory to utilize such pulling means as acable leading from the hopper upward out of the trench to a tractor orthe like. Consequently, the present system comprehends a uniquecombination of the trench-excavating apparatus with thegravel-dispensing apparatus.

A pair of hooks 63, 64 are provided on the forward end of hopper 5 sothat pan 49 can be cradled in these hooks when it is desired totransport the hopper outside the trench. When the pan is thus cradled inthe hooks, it will be appreciated that a pull bar (not shown) of asuitable conventional type may be attached centrally of cross member 62for purposes of providing a point of attachment for pulling the hopperabout by means of a tractor, truck or similar road vehicle. For purposesof such open road travel, wheel members (not shown) such as a trolley orthe like may be positioned beneath the hopper for rollably supportingit.

In laying a bed of grave] in a trench employing the system of thepresent invention, the empty hopper, with the plow 30 disposed in itsmost forward position, is lowered into the trench. Because the plow doesnot appreciably project beyond the end of the hopper, the device can belocated at the end of the trench so as to commence laying the gravel bedat the end of the trench and thus utilize all the excavated area. Alifting lug 65 secured on the top of the hopper 5 provides a means forgrasping it to raise and lower it into the trench. In the usualoperation a backhoe fitted with a cable on its bucket for engaging thelifting lug 65 is utilized for lowering the hopper into the trench. Oncein position within the trench, the hopper is loaded with gravel directlyfrom a dump truck. Not infrequency, as much as 3-4 tons of gravel aredumped into the hopper. It will be appreciated that the hopper may belowered into the trench and filled with gravel by a single operator in avery brief period of time. i

The gravel is metered from the hopper through slots 13, 14 into thespace beneath the hopper.

Upon the hopper being initially placed within the trench and loaded withgravel, the gravel flows from the hopper through slots 13 and 14 andsubstantially fills the space immediately beneath the rear half of thehopper. The gravel is restrained against lateral flow by the chutes 38,39 at the front end of the hopper. There are no panels provided on therear one-half of the sides of the hopper so that gravel is free to flowfrom beneath the hopper laterally into the space the trench proper. Thisinitial flow of gravel into the space beneath the hopper causes gravelto be dispersed into the trench commencing at the very end of theexcavated trench. After the space beneath the rear half of the hopper isfilled by the gravel, the toothed bucket of the backhoe is engaged withthe drawbar pan to pull the hopper along the length of the trench. Asthe hopper is pulled along the trench, gravel is metered through chutes38, 39 on opposite sides of the hopper. As the hopper progressesforwardly, the gravel enters each chute at the most forward end of thechute and flows downwardly through the chute between the side panel andfender defining the chute. The two separate streams of gravel flowingthrough the chutes converge beneath the hopper at a point about halfwaybetween the ends of the hopper and form a single bed of gravel having arudimentary furrow along its centerline. This delayed convergence of thegravel creates an open space which is free of gravel adjacent theforward end of the hopper so as to provide an area within which thedrawbar mechanism can operate. Specifically, within this gravel-freearea there are mounted the springs and chains leading from beneath thehopper to he forward end and engaging the drawbar pan. When gravel areallowed to flow into the area immediately beneath the hopper adjacentits forward end, these gravel become lodged in the springs and chainsand destroy their ability to function. Further, the rudimentary furrowaffords a clearance for the collars 25, 26 and their supportingstructure. It has been found to also enhance subsequent furrowing byinitially positioning the gravel laterally of the bed centerline andlessen the work required of the plow.

Further as the hopper is pulled along the trench, the depth of thegravel bed is established by the height at which the hopper ismaintained above the bottom of the trench and by the bottom edge of therear end of the hopper which acts as a screed to level the bed of gravelwithin the trench. It has been found preferable to construct the hopperof a width less than the width of the excavated trench to permit freemovement of the hopper within the trench and to permit the constructionof curved trenches. This design causes the hopper to be more narrow thanthe width of the trench. Accordingly, it has been necessary, forexample, in laying a gravel bed of 12 inch thickness to support thehopper about 17 inches above the bottom of the trench when the trench is36 inches wide. Other relative heights of the hopper above the trenchfor selected trench widths may be readily ascertained from the aboveguidelines to achieve a desired depth of gravel bed. Because the presentinvention is capable of laying down a measured and uniformly thick bedof gravel, the quantity of gravel required for a particular job can becalculated beforehand so as to avoid waste. This savings alone has beenfound to be very significant.

Upon commencement of movement of the hopper, the plow blade 30experiences a drag and is caused to slide within collars 25 and 26 untillug 29 on the plow beam 28 has contacted the most forward edge of collar26. At this point in the forward progression of the hopper, the plowblade is caused to trail behind the hopper and displace gravel laterallyof the center line of the gravel bed to create a longitudinal furrowalong the length of the bed. The action of the plow 30 is enhanced bythe fact that the rudimentary furrow created by the two streams ofgravel flowing from the hopper is redefined in part by the convergingdepending portion 24 of rear end 9. It has been found preferable thatplow 30 to be mounted on a plow beam of sufficient length so that thegravel of the bed will seek their own level and come to rest prior tocommencement of the furrowing action of the blade 30. In a preferredembodiment, plow blade 30 is extended a distance of at least about 18inches to the rear of the hopper. When the plow blade is positionedcloser to the hopper than this distance, it has been found that thenewly laid bed is unstable and the furrowed gravel tends to roll or fallback into the furrow thereby negating the desired action of the plow. Ithas also been found that the desired furrow is preferably obtained whenthe plow blade is provided with a negative angle of attack. That is, itis preferred that the plow blade be tilted at an angle of between about10 and 30 with respect to the vertical so that the pointed tip of thetriangular blade is positioned a short distance more rearwardly than theuppermost leading edge of the blade. This angle of inclination of theblade has been found to force the gravel laterally of the center line ofthe bed as well as afiord a degree of compaction of the gravel in thesides of the furrow by the blade wings thereby insuring that the gravelmaintain their laterally displaced position and define the desiredfurrow.

In the preferred embodiment, the side panels 22, 23 seal against lateralflow of the bottom of the hopper. This lateral restraint against gravelfrom beneath the most forward onehalf of the bottom of the hopper. Thislateral restraint against gravel flow reduces the friction created bygravel engaging the sides of the trench and tending to bind the hopperagainst forward motion. The panels also prevent the gravel from flowingunderneath the leading edges of the runners and impeding the desiredfree sliding movement of the hopper.

It will be appreciated that the system of the present invention providesthe means whereby a single workman can construct a drain field in lesstime that heretofore has been possible for two or three workmen. Thesavings in gravel and time are readily recognized, as is the moreuniform nature of the product provided by the present system.

While a preferred embodiment has been shown and described, it will beunderstood that there is no intent to limit the disclosure, but rather,it is intended to cover all modifications and alternate constructionsfalling within the spirit and scope of the invention as defined in theappended claims. For example, whereas it is preferred for reasons ofeconomy and expediency of operation to engage the drawbar with thebackhoe bucket, the backhoe and hopper may be connected by means of aretractable boom extending between these two units.

What is claimed is:

1. A system for constructing a drain line including a drain tiledisposed in a gravel bed laid in the bottom of a narrow trenchcomprising mobile power means adapted to excavate said trench inincrements of length from a position outside said trench and havingdigging means for lowering into said trench, dispensing means disposedin said excavated trench and movably supported ofi the bottom of saidtrench a preselected distance for laying a bed of particulate matter inthe bottom of said trench, drawbar means comprising connector meansanchored to said dispensing means and releasably interconnecting saiddigging means of said mobile power means and said dispensing means forpulling said dispensing means along said trench in increments ofmovement approximately equal to the increments of excavation of saidtrench.

plow means trailing said dispensing means as it is pulled along saidtrench and displacing particulate matter laterally of the approximatecenterline of said bed to define a longitudinal furrow for receivingsaid drain tile.

2. The system of claim 1 wherein said drawbar means retracts to aposition of noninterference with subsequent excavation when said powermeans and dispensing means are disconnected.

3. The system of claim 1 wherein said connector means is anchored byflexible strands secured at one of their respective ends to saiddispensing means and at their other respective ends to said connectormeans.

4. The system of claim 1 wherein said connector means is spring-biasedin a retracted position adjacent said dispensing means.

5. The system of claim 1 wherein said mobile power means comprises abackhoe having a toothed bucket digging means and said drawbar meanscomprises a connector releasably engagable by the teeth of said toothedbucket of said backhoe.

6. The system of claim 1 wherein said dispenser means comprises a hopperadapted to receive said particulate matter and having a partial bottomdefining at least two laterally disposed elongated openings on oppositesides of said bottom and extending rearwardly from the forward end ofsaid hopper at least a major part of the length of said hopper,

a dispensing chute depending from at least the most forward portion ofeach of said lateral openings providing laterally disposed guide pathsfor the flow of particulate matter from said hopper through saidopenings into the trench beneath said dispenser means in the form ofrows defining at least a rudimentary furrow therebetween.

7. Apparatus for depositing particulate matter in position for receivingdrain tile within a trench defined by side walls and a bottom comprisinga hopper having side and front and rear end walls and adapted to bereceived within the confines of said trench, a longitudinally gabledpartial bottom in said hopper and in combination with the side walls ofsaid hopper defining at least two substantially parallel longitudinalopenings laterally separated in the lower portion of said hopper formetering said particulate matter from said hopper, chute means disposedbeneath about the forward one-half of each of said longitudinal openingsto guide particulate matter into said trench in the form of at least twostreams converging toward the approximate centerline of said trench,friction means disposed beneath said hopper and supporting said hopperabove the bottom of said trench for movement of said hopper along thelength of said trench,

mobile power means for propelling said hopper along the length of saidtrench, whereby said particulate matter is deposited from said hopperinto said trench in a relatively unifomily thick layer as said hopper ismoved along the length of said trench, and furrowing means trailing saidhopper and furrowing said layer of particulate matter along itsapproximate centerline.

8. The apparatus of claim 7 and including retractable drawbar meansanchored to said hopper for releasably joining said mobile power meansto said hopper in substantially horizontal pulling alignment for pullingsaid hopper along said trench in increments of movements.

9. The apparatus of claim 7 wherein said furrowing means comprises aplow having a pair of generally right triangular wing portions disposeduprightly in side-by-side relation and defining an obtuse angle, saidcontacting sides further defining a centerline and a downwardlyprojecting digging tip on said plow, said centerline being inclined atan anglebetween about 0 and 30 with respect to the vertical to positionsaid digging tip of said blade more rearwardly than the top edge of saidblade with respect to the direction of forward travel of said plow.

I Column Column Column Column Column 5,

Column 6, "bottom",

,add half of the NITED STATESPATENT OFFICE v v CERTIFICATE or;ZGRRECTION v v 'PetehpNo, 3,664,137t v I v I l mrentofls Ja m'e s ElLett I1: is certified that. error appears in ,thefabo ve-identifiedpatent; and that said-Letters Patent are hereby corrected as shownbelow: 1

Column '1, line's 2-32, Change "particular? 5- p ti ijlaf, J

line-8, 1

lines 11 1 line 2 6;- line 47,

line 3 Column 6; lines 38-40; delete "This ,-l atera l4 restraint.against gravel from beneath the most forward one-half of the-bottom 30f.the hopper. a

' Column 6,11% 73, beg'i nn ing t 'd rawbar begin new paragraph whichends at the end of "line 4 offlColumn 7.

COlUmn e 38, following ',"fl.OW' beneath the most forward one-half ISigned and sealed this b th dayof-Dece mbfer. 1972;

. Dated Mai 23,- 1972 i insert commaef-ter "Vertical":

nsert comma after "operationh Jni ff qu'ency" l'n'ff q v y L? delete"the space" change "h'" uto the after the vword "th'e". and before theword gravel from be'neaththe most forward one' 7 (SEAL) Attest:

EDWARD M.FLETCHER,JB.-. Attestin'g Offioer ROBERT GOT'ISCHALKCommissioner of Patents insert h of the gravel from v

1. A system for constructing a drain line including a drain tiledisposed in a gravel bed laid in the bottom of a narrow trenchcomprising mobile power means adapted to excavate said trench inincrements of length from a position outside said trench and havingdigging means for lowering into said trench, dispensing means disposedin said excavated trench and movably supported off the bottom of saidtrench a preselected distance for laying a bed of particulate matter inthe bottom of said trench, drawbar means comprising connector meansanchored to said dispensing means and releasably interconnecting saiddigging means of said mobile power means and said dispensing means forpulling said dispensing means along said trench in increments ofmovement approximately equal to the increments of excavation of saidtrench. plow means trailing said dispensing means as it is pulled alongsaid trench and displacing particulate matter laterally of theapproximate centerline of said bed to define a longitudinal furrow forreceiving said drain tile.
 2. The system of claim 1 wherein said drawbarmeans retracts to a position of noninterference with subsequentexcavation when said power means and dispensing means are disconnected.3. The system of claim 1 wherein said connector means is anchored byflexible strands secured at one of their respective ends to saiddispensing means and at their other respective ends to said connectormeans.
 4. The system of claim 1 wherein said connector means isspring-biased in a retracted position adjacent said dispensing means. 5.The system of claim 1 wherein said mobile power means comprises abackhoe having a toothed bucket digging means and said drawbar meanscomprises a connector releasably engagable by the teeth of said toothedbucket of said backhoe.
 6. The system of claim 1 wherein said dispensermeans comprises a hopper adapted to receive said particulate matter andhaving a partial bottom defining at least two laterally disposedelongated openings on opposite sides of sAid bottom and extendingrearwardly from the forward end of said hopper at least a major part ofthe length of said hopper, a dispensing chute depending from at leastthe most forward portion of each of said lateral openings providinglaterally disposed guide paths for the flow of particulate matter fromsaid hopper through said openings into the trench beneath said dispensermeans in the form of rows defining at least a rudimentary furrowtherebetween.
 7. Apparatus for depositing particulate matter in positionfor receiving drain tile within a trench defined by side walls and abottom comprising a hopper having side and front and rear end walls andadapted to be received within the confines of said trench, alongitudinally gabled partial bottom in said hopper and in combinationwith the side walls of said hopper defining at least two substantiallyparallel longitudinal openings laterally separated in the lower portionof said hopper for metering said particulate matter from said hopper,chute means disposed beneath about the forward one-half of each of saidlongitudinal openings to guide particulate matter into said trench inthe form of at least two streams converging toward the approximatecenterline of said trench, friction means disposed beneath said hopperand supporting said hopper above the bottom of said trench for movementof said hopper along the length of said trench, mobile power means forpropelling said hopper along the length of said trench, whereby saidparticulate matter is deposited from said hopper into said trench in arelatively uniformly thick layer as said hopper is moved along thelength of said trench, and furrowing means trailing said hopper andfurrowing said layer of particulate matter along its approximatecenterline.
 8. The apparatus of claim 7 and including retractabledrawbar means anchored to said hopper for releasably joining said mobilepower means to said hopper in substantially horizontal pulling alignmentfor pulling said hopper along said trench in increments of movements. 9.The apparatus of claim 7 wherein said furrowing means comprises a plowhaving a pair of generally right triangular wing portions disposeduprightly in side-by-side relation and defining an obtuse angle, saidcontacting sides further defining a centerline and a downwardlyprojecting digging tip on said plow, said centerline being inclined atan angle between about 10* and 30* with respect to the vertical toposition said digging tip of said blade more rearwardly than the topedge of said blade with respect to the direction of forward travel ofsaid plow.